In the field of the electronic device such as a server, focus is paid on an optical transmission technique in which a plurality of server racks are connected one another with an optical fiber, in order to increase the speed of signal transmission in the electronic device.
In the optical transmission technique, an optical element configured to transmit and receive optical signals and a circuit element, such as a drive IC, configured to drive the optical element are used, and the optical element is optically connected to the optical fiber.
The optical element and the circuit element are connected to each other with a metal wire. The metal wire is preferable to be as short as possible to reduce wiring delay so that faster signal transmission can be achieved.
Moreover, the optical transmission technique has room for improvement also in view of reduction in optical signal loss.